Hello,
do you have Tectia on Windows side, on z/OS side or on both sides?

1) If you have Tectia Server for IBM z/OS installed and you are initiating connections from the mainframe side towards Windows SFTP server (Tectia or other SFTP server on that Windows machine), then you can just use normal SFTP put/get commands to transfer files/datasets back and forth.

Note: If you need to enable automatic codeset conversion, like ASCII<->EBCDIC (and maybe also end line delimiter change), you need to use ASCII transfer mode. When you enable ASCII transfer mode, Tectia Client on z/OS will convert codesets/end line delimiters automatically for you.

2) If you are using other SFTP file transfer client tools on z/OS and you are initiating connections from the z/OS towards Windows Tectia Server, then you need to check that your z/OS SFTP client can perform all necessary conversions for you unless you are just using BINARY file transfer mode.

3) When you are connecting to Tectia Server on IBM z/OS, then in Tectia-to-Tectia connections, you can use normal SITE/LSITE command syntax. If you are using some other SFTP client (non-Tectia) and you are connecting to Tectia Server on IBM z/OS, then you can use our File Transfer Advisor syntax (FTADV) to send DCB parameters to our z/OS SFTP server.

Tectia Client/Server shouldn't have any restrictions in compatibility as long as the other side is obeying standards.

Do you have more information about your current use case? Like for example, who is initiating the connection? Which client/server components are in use? Is conversion needed?